The Koch brothers’ political operation has increasingly come to resemble its own political party — and later this month in San Diego, it will hold what amounts to its most ambitious convention to date.

Many of the dozens of rich conservative invitees are expected to write huge checks to a pool of cash distributed among Koch-approved groups, potentially boosting the Kochs’ 2012 spending plan beyond their historic $395 million goal. And it’s also a chance for the Kochs to show off their increasingly robust political machine, including a growing voter database project called Themis that played a major role in conservatives’ recent efforts in Wisconsin and in which POLITICO has learned Koch operatives have discussed investing $20 million.